The basic difference between Michigan State and Illinois, two of the top teams in college basketball this season, is perhaps best illustrated by the nicknames of their stars.

Michigan State rocks and rolls with a man called "Magic" while Illinois sweats and strains with one known as the "Incredible Hulk."

The Spartans, led by Earvin (Magic) Johnson, are flamboyant speedsters, cool and confident with their No. 1 ranking. Their game plan is simple -- just outscore the opposition, no matter how many points that takes.

The Illini, led by Derek (Incredible Hulk) Holcomb, are slower and much more conservative in style, and somewhat surprised themselves that they are undefeated after 14 games. Their game plan is simple, too, yet at the opposite end of the spectrum from that of Michigan State. They try to keep their opponents from outscoring them, no matter how few points that takes.

Both ways work.

The biggest crowd in the Univezbity of Illinois basketball history, more than 16,200, will squeeze into Assembly Hall on the Champaign campus tonight when Michigan State comes to town for a Big Ten showdown.

The Spartans are used to big games, the Illini are not. Illinois, which won only 13 games all of last season, suddenly finds itself ranked third in the nation in the UPI poll and fourth in the AP poll, and one of only four unbeaten teams left in the country going into last night's games (Arkansas, Indiana State and Temple are the others).

The Illini so far have won more games this season than any other college team.They also have the longest winning streak, 15 straight over two seasons.

Coach Lou Henson is trying to remain calm.

"I never thought I'd be coaching a 14-0 team," he said. "But I sure got one.

"For us, the Michigan State game is no different than any other. I've seen a team get up too high from one game and then lose the next five or six straight. We don't want that to happen to us."

Actually, Illinois' fortunes started imporoving two years ago when the 6-foot-11 Holcomb got fed up with Bobby Knight and the University of Indiana, and transferred to Illinois.

He had to sit out last season, but with him in the middle now Illinois has an intimidating center for the first time in a long time.

Holcomb did not come in exactly one piece, however. He needed operations on both feet, but once he could walk, the Illini were ready to climb.

Most experts felt that they were at least a year away because the best senior on the team, Levi Cobb, is no better than the sixth man. Even when they coasted to seven straight victories, not much notice was taken. But then they went to the Kentucky Invitational with three other highly ranked teams, Kentucky, Syracuse and Texas A&M.

Illinois won the tournament, beating Syracuse and A&M, and the rest of the Big Ten gulped.

"We thought they'd have a good club, but we didn't dream they would be 14-0," said Michigan State Coach Jud Heathcote. "I looked at their early schedule and thought they were just lucky. But when they won the Kentucky tournament, they showed they are for real."

Almost as impressive as its record is the fact that Illinois has played its last seven games on the road and only four of its 14 victories have come at home.

Illinois plays basically a man-to-man defense with its strength in the front court.

Holcomb already has blocked 58 shots and helped force Illinois opponents to shoot a lowly 37 percent, making Illinois the best in the country in that category. Holcomb also is averaging 10 points and seven rebounds a game.

The leading Illinois scorer is 6-7 guard Mark Smith, who is averaging 15.4 points and 4.4 assists.

The other starters are 6-6 Neil Bresnahan and 6-8 Eddy Johnson at the forwards and 6-2 Rob Judson at the other guard.

Cobb, Steve Lanter and James Griffith are the top reserves. Illinois relies heavily on balance and depth.

The Spartans, however, belong to one man -- Magic Johnson.

"He is the key, the catalyst, the one who makes us go," said Heathcote, "but he is not a one-man show."

If Johnson shot more and better, he would be a one-man show, but his forte is handling the ball. At 6-8, he is a true guard, averaging more than 10 assists a game with most of them bordering on being spectacular.

The Spartans, 9-1 and top-ranked in both wire service polls, have lost only to North Carolina by one point at North Carolina.

They were 25-5 last year and would have made it to the final four had Kentucky not beaten them, 52-49, in the Mideast Regional final.

They lost only one starter from last year, Bob Chapman, and his place has been taken by Ron Charles, the sixth man a year ago.

Michigan State does not have an intimidating big man. Jay Vincent, 6-8, is the center, but Charles and leading scorer and rebounder Gregory Kelser are both 6-7, and with Johnson at 6-8, the Spartans are not a short team. The other starter is 6-2 Terry Donnelly.

All starters except Donnelly are averaging in double figures, Kelser at 17.5 Vincent at 15.9, Johnson at 14 and Charles at 12.3. p